Printing stencils coated in this way are known, as shown by EP-A-0,492,351, EP-A-0,558,098 or EP-A-0,590,164. Considered individually, in EP-A-0,492,351 a method and a corresponding apparatus for the production of a printing stencil of this kind is proposed. There, preferably a powder, such as for example talcum powder, is applied to the screen, so that the ink sprayed on thereafter does not run, but forms exact contours. A disadvantage of this arrangement may be seen in the use of this powder which always forms a mist at the workplace and which is therefore detrimental to the environment
EP-A-0,558,098 describes the design of tailstocks which are provided with steps so that tubular screens having different diameters can be centered. The production of such tailstocks is relatively complicated and therefore costly, since, in comparison with simple known tailstocks, merely exchanging these would clearly make the extra cost a major factor.
Finally, EP-A-0,590,164 shows a method, in which the covering layer is formed from a high-viscosity layer. An emulsion of a synthetic resin lacquer is proposed as a material for this high-viscosity layer. However, such a material has a high adhesive force on the screen, and there is no provision for washing out after exposure, since the covering fluid is to be resistant to abrasion and to chemical influences of the printing chemicals.